1. Field of the Invention
The present invention relates to a keypad panel, and in particular to a metallic keypad panel assembly.
2. Description of Prior Art
Keypad panel has become a necessary hardware for a portable electronic device. The surface of the keypad on the keypad panel is provided with numerals, characters, phonetic symbols, roots for an input method and various functional icons, so that a user can input data according to the icon displayed on the surface of the keypad or perform various functions of the portable electronic device. Therefore, for a portable electronic device, the keypad panel is a very important input means.
For example, a conventional metallic keypad panel on a portable electronic device is shown in FIGS. 1(a) and 1(b) (Japanese Laid-Open Patent Publication No. 2007-115633). In manufacturing the metallic keypad panel 10a disclosed in FIG. 1, a metallic plate 1a is prepared first. Then, a first etching process is applied to the metallic plate 1a, thereby forming hollowed portions 2a having characters, numerals and marks. After etching the hollowed portions 2a, a second etching process is applied to one side surface of the metallic plate 1a. After the second etching process, one side surface of the metallic plate 1a is formed thereon with a cross-like recessed portion 2b. Then, the metallic plate 1a is disposed in a mold. A resin is injected into the mold, so that the resin can fill the hollowed portions 2a and the cross-like recessed portion 2b. The cross-like recessed portion 2b allows the resin to be combined on the metallic plate 1a firmly, thereby forming a resin layer 3a. After the metallic plate 1a is combined with the resin layer 3a, the metallic plate 1a is cut to form keypad caps 11a. Then, one side surface of the resin layer 3a is printed with a printing layer 4a. An adhesive layer 5a is applied on the printing layer 4a. The resin layer 3a is adhered on elastic bodies 7a of a base 6a, so that a protrusion 71a of the elastic body 7a can press against a metal dome 8.
In manufacturing the above-mentioned metallic keypad panel 10a, since two or more etching processes should be applied to the metallic plate 1a, more work hours and a large number of processes are necessary. Further, a gap is formed between each keypad cap 11a, and the gap may be filled by dusts or penetrated by liquid easily. As a result, the metallic keypad caps 11a cannot be pressed smoothly or an internal short circuit may occur. Further, one side surface of the metallic plate 1a does not provide any reflective effect of a particular luster. Therefore, the external appearance and the overall visual effect of the metallic keypad panel 10a are dull.